The present invention relates to the use of a polysilanesiloxane in epoxy resins to produce heat curable epoxy compositions. More particularly, the present invention relates to the use of such polysilanesiloxane in combination with an effective amount of a platinum hydrosilylation catalyst which can enhance the rate of cure of the resulting heat curable epoxy compositions.
Prior to the present invention, as shown by Crivello, U.S. Pat. No. 4,173,551, heat curable epoxy compositions were provided employing a diaryliodonium salt initiator in combination with a copper salt. Polymerization of epoxy resins, for example, epoxy functional siloxanes are also shown in copending application Ser. No. 07/473,802, filed Feb. 2, 1990, assigned to the same assignee as the present invention. As taught in 07/473,802, cure of epoxy compounds also can be effected utilizing a platinum catalyst and a silicon hydride. Additional procedures for effecting the cure of certain epoxy resins, such as epoxysiloxanes, are shown by E. P. Plueddemann et al, Jour. of Amer. Chem. Soc., Volume 81, 2632-2635 (1959).
Although several procedures are available for effecting the thermal cure of epoxy resins, new methods are constantly being investigated to develop compositions having an extended shelf life at ambient temperatures which are curable within a reasonable time at temperatures less than 200.degree. C.